Mechanosensitive cation channel with low conductance and high activation threshold (PubMed:30382938, PubMed:31587869, PubMed:37543036). In contrast to TMEM63B, does not show phospholipid scramblase activity (PubMed:39716028). Acts as a regulator of lysosomal morphology by mediating lysosomal mechanosensitivity (By similarity). Important for the baby's first breath and respiration throughout life (PubMed:38127458). Upon lung inflation conducts cation currents in alveolar type 1 and 2 cells triggering lamellar body exocytosis and surfactant secretion into airspace (PubMed:38127458). Also acts as an osmosensitive cation channel preferentially activated by hypotonic stress (By similarity). {ECO:0000250|UniProtKB:Q91YT8, ECO:0000269|PubMed:30382938, ECO:0000269|PubMed:31587869, ECO:0000269|PubMed:37543036, ECO:0000269|PubMed:38127458, ECO:0000269|PubMed:39716028}. This is the function of ENSG00000196187 (TMEM63A, transmembrane protein 63A).